This application relates to a contactless electronic control system. It relates especially to a throttle/brake control system for a modular motorized wheel assembly.
There are numerous vehicles in use today which have battery-powered electric motors to drive the wheels of the vehicle. These include bicycles, adult tricycles, wheelchairs, motor scooters, golf carts, all terrain vehicles, etc. In many such vehicles, the electric motor is mounted to the vehicle frame with the motor output being coupled to the wheels by way of a chain drive, gear train or the like. More preferably, the motor is incorporated right into the wheel hub thereby minimizing the size, weight, complexity and cost of the drive system. Examples of such in-hub motors are disclosed in U.S. Pat. Nos. 572,036; 2,514,460 and 3,921,741.
A particularly desirable, modular motorized wheel hub assembly for vehicles of this type is disclosed in pending application Ser. No. 09/076,317, May 11, 1998, the contents of which is hereby incorporated herein by reference.
With modular motorized wheels of the type of interest here, it is essential that suitable control means be provided that are capable of applying the appropriate control voltages to the wheel motor to enable the wheel motor to operate in a reliable fashion. Invariably, such control means include a throttle or throttle/brake control which the vehicle operator may manipulate to accelerate the decelerate the associated vehicle. For the most part, conventional electric motor controllers, particularly those used to control electric bicycles, golf carts and other electric vehicles operate satisfactorily. However, they do have certain disadvantages which limit their wider use and application. More particularly, some such controllers are complex and costly. Others require a large number of moving, contacting parts which are prone to wear thereby limiting the useful life of the controller. Others are not suitable for all weather outdoor applications, such as required on bicycles.
There do exist electromagnetic motor controllers which incorporate Hall Effect devices; see e.g., U.S. Pat. No. 5,450,054. However, those prior controllers require many such devices in order to operate properly. Therefore, they are needlessly expensive and hence impractical for use on electric bikes and other such small vehicles.
Also, those prior controls employing Hall Effect devices are not adequately shielded so that they may be affected by nearby magnetic and ferro-magnetic objects. That is, in response to those objects, the controller may develop spurious signals which can cause the associated motor to spontaneously accelerate or decelerate. Nor do they have a natural, stable zero magnetic field position; i.e., a natural neutral throttle position. Needless to say, these factors can place the vehicle rider in serious danger.